Episode 5 of "Spring of Youth" kicks off with a poignant flashback, where a youthful Kim Bom triumphantly claims first prize at a music competition. Overflowing with excitement, she dials her mother, who is navigating the treacherous roads amidst a downpour, to share the joyous news. With a spark of ambition, Bom inquiries about attending winter school alongside the offspring of Choijin Group, a fellow pupil at her school. Her mother, ever supportive, assents, but fate intervened in the form of a devastating accident shortly thereafter.
Bom, grappling with grief, subsequently inks her name on an organ donation consent form. In a haunting vision, her mother's spirit questions her actions, wondering why she opted for donation instead of waiting for a miracle. Snapping back to the present, Bom awakens with a start, inquiring about Sa Gye's whereabouts to Tae-yang, who manufactures a tale about Sa Gye indulging in a night out with a friend, only to end up slumbering at his former J&J Entertainment manager's residence.
Ja-young later drops a bombshell, revealing that Sa Gye had been probing inquiries about the house and Bom's mother the previous evening. Determined to uncover the truth, Sa Gye ventures to the hospital, seeking the identity of his anonymous organ donor, only to find the information shrouded in confidentiality. Nevertheless, fragments of Bom's mother's final moments flash through his mind, guiding him to the accident site where a harrowing realization dawns – Cho Sang-heon was responsible for Bom's mother's demise. Unfortunately, Min-cheol catches him in this introspective moment, alerting Sang-heon to the urgency of taking preemptive action.
A nostalgia-tinged flashback transports us to Cho Ji-na calling Bom, soliciting more songs. Bom, assertive and autonomous, reveals her intentions to produce her own music, prompting Ji-na to mistakenly assume it's for Sa Gye. In contemporary times, Ji-na extends an olive branch, offering her original composition titled "See You Later" to replace the plagiarized track, seeking redemption in the wake of controversy.
Bom and Ja-young are subsequently summoned to the precinct, where a policeman informs them that someone has stepped forward as a witness to the accident. Upon Sa Gye's arrival, he hesitates at the station's threshold upon spotting Bom within. The officer reveals that the witness claims to have been fourteen at the time of the occurrence, prompting them to suspect a fabricated report and proceed to depart.
Min-cheol approaches Tae-yang, expressing his understanding of his decision to withdraw from medical school. Instead, he urges Tae-yang to embark on a new journey by joining J&J and ascending to the role of The Crown's freshest member. Tae-yang unveils a surprising twist, revealing that the position had always been rightfully his.
A nostalgic flashback unveils young Tae-yang auditioning for The Crown with fervent passion. It transpires that he had clinched the top spot but relinquished it due to his commitment to medical school. Consequently, Sa Gye secured the spot solely because Tae-yang's path diverged. However, this revelation sits heavily on Tae-yang, compelling him to leave abruptly.
Following Ja-young's directives, Gyu-ri accompanies Bom on a shopping spree followed by a delightful meal. Sa Gye trails behind them, his demeanor torn between conflicting emotions. Meanwhile, within the confines of a rehearsal studio, The Crown meticulously practices Ji-na's new song titled "See You Later," which unexpectedly bears a striking resemblance to Bom's melody. Sang-heon, captivated by the harmony, finds himself elated. His subsequent encounter with Min-cheol leads to a suggestion: embracing Tae-yang as the band's new helm.
Sa Gye receives an urgent call from Tae-yang, who reproaches him heatedly for causing Bom undue worry. Soon after, Sa Gye's former manager arrives home, burdened with tales of the band's latest musical troubles. Intrigued, Sa Gye tasks him with uncovering the mysteries surrounding Sang-heon's car from six years past.
In parallel, Tae-yang informs Bom of his intentions to confront Sa Gye, inquiring if she wishes to accompany him. Sa Gye, startled to see Bom, endeavors to mask his surprise. Bom, unimpressed, scolds him before insisting he attend band practice at 5 pm. To her astonishment, Sa Gye declares his resignation from the band, citing a lack of enjoyment, and hints at an impending relocation. Tae-yang, incensed, responds with a punch and storms off.
Later, Jin-gu steps into Gyu-ri's residence as Sa Gye's replacement, only to receive a text canceling band practice. Meanwhile, Tae-yang treats Bom to drinks, aiming to lift her spirits. Amid playful antics on their way back, Tae-yang, impulsively, confesses his feelings for Bom. She, however, gently rejects him, revealing her affections lie elsewhere, and departs.
Sa Gye, driven by a fit of recklessness, ventures to Seung-su's place and vandalizes Sang-heon's car with a microphone stand. He grants Sang-heon a chance to confess, but Sang-heon dares him to produce evidence. Seung-su, catching him with the stand, recognizes it as the same one that once injured his eye. Furthermore, Seung-su reveals that Sang-heon has never owned an SUV.
The following morning, Bom receives a call from Min-cheol, who presents her with a golden opportunity for Tae-yang and insists she lets him pursue it. Bom discovers a package from Tae-yang containing hangover medicine and a new phone to replace her cracked one. However, she returns the gifts, unable to accept either the phone or his affections.
She subsequently ventures into their former band room, where she indulges in nostalgic reveries of the joyful moments they once shared. Soon after, the other band members come to the disheartening realization that their musical journey is coming to an end. They confront Bom in the very sanctuary of their shared passion, and she solemnly informs them that their band's future is bleak. With a tone of encouragement, she urges Tae-yang to pursue his heart's desire unwaveringly.
The scene shifts to Bom purchasing a sleek new phone, deliberately leaving behind the photos of the band in her old device, symbolizing a tentative detachment from the past. Later, in a conversation with Min-cheol, he expresses gratitude for her allowing Tae-yang to embark on his own path. However, the façade of resilience crumbles upon her return home, as Bom succumbs to an emotional breakdown.
At her part-time job, the blow strikes again when the melancholic strains of The Crown's new song echo through the air, serving as a poignant reminder of lost times at the conclusion of Spring of Youth Episode 5.
